From 65fd5ac7dd507c462ceb8f80b5a017c8cede86a0 Mon Sep 17 00:00:00 2001
From: Adam Storr <astorr@gmail.com>
Date: Sat, 2 Jun 2018 21:36:20 +0100
Subject: [PATCH] Using enums as generic constraints in 7.3

---
 src/StrategyPatternExample.sln                           | 2 +-
 src/StrategyPatternExample/IMathOperator.cs              | 8 +++++---
 src/StrategyPatternExample/MathStrategy.cs               | 4 ++--
 src/StrategyPatternExample/Operators/AddOperator.cs      | 2 +-
 src/StrategyPatternExample/Operators/DivideOperator.cs   | 2 +-
 src/StrategyPatternExample/Operators/MultipleOperator.cs | 2 +-
 src/StrategyPatternExample/Operators/SubtractOperator.cs | 2 +-
 src/StrategyPatternExample/Startup.cs                    | 8 ++++----
 src/StrategyPatternExample/StrategyPatternExample.csproj | 8 ++++++++
 9 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/src/StrategyPatternExample.sln b/src/StrategyPatternExample.sln
index 68af79a..23f5114 100644
--- a/src/StrategyPatternExample.sln
+++ b/src/StrategyPatternExample.sln
@@ -3,7 +3,7 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 15
 VisualStudioVersion = 15.0.27428.1
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "StrategyPatternExample", "StrategyPatternExample\StrategyPatternExample.csproj", "{33A47031-B45D-4CF2-8EA3-7404D506E258}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "StrategyPatternExample", "StrategyPatternExample\StrategyPatternExample.csproj", "{33A47031-B45D-4CF2-8EA3-7404D506E258}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
diff --git a/src/StrategyPatternExample/IMathOperator.cs b/src/StrategyPatternExample/IMathOperator.cs
index 7451c71..2fe3478 100644
--- a/src/StrategyPatternExample/IMathOperator.cs
+++ b/src/StrategyPatternExample/IMathOperator.cs
@@ -1,8 +1,10 @@
-namespace StrategyPatternExample
+using System;
+
+namespace StrategyPatternExample
 {
-    public interface IMathOperator
+    public interface IMathOperator<out T> where T : Enum
     {
-        Operator Operator { get; }
+        T Operator { get; }
 
         int Calculate(int a, int b);
     }
diff --git a/src/StrategyPatternExample/MathStrategy.cs b/src/StrategyPatternExample/MathStrategy.cs
index ed864a9..ad58814 100644
--- a/src/StrategyPatternExample/MathStrategy.cs
+++ b/src/StrategyPatternExample/MathStrategy.cs
@@ -6,9 +6,9 @@ namespace StrategyPatternExample
 {
     public class MathStrategy : IMathStrategy
     {
-        private readonly IEnumerable<IMathOperator> _operators;
+        private readonly IEnumerable<IMathOperator<Operator>> _operators;
 
-        public MathStrategy(IEnumerable<IMathOperator> operators)
+        public MathStrategy(IEnumerable<IMathOperator<Operator>> operators)
         {
             _operators = operators;
         }
diff --git a/src/StrategyPatternExample/Operators/AddOperator.cs b/src/StrategyPatternExample/Operators/AddOperator.cs
index 1e127f1..24be84b 100644
--- a/src/StrategyPatternExample/Operators/AddOperator.cs
+++ b/src/StrategyPatternExample/Operators/AddOperator.cs
@@ -1,6 +1,6 @@
 namespace StrategyPatternExample
 {
-    public class AddOperator : IMathOperator
+    public class AddOperator : IMathOperator<Operator>
     {
         public Operator Operator => Operator.Add;
 
diff --git a/src/StrategyPatternExample/Operators/DivideOperator.cs b/src/StrategyPatternExample/Operators/DivideOperator.cs
index c428301..fd22154 100644
--- a/src/StrategyPatternExample/Operators/DivideOperator.cs
+++ b/src/StrategyPatternExample/Operators/DivideOperator.cs
@@ -2,7 +2,7 @@
 
 namespace StrategyPatternExample
 {
-    public class DivideOperator : IMathOperator
+    public class DivideOperator : IMathOperator<Operator>
     {
         public Operator Operator => Operator.Divide;
 
diff --git a/src/StrategyPatternExample/Operators/MultipleOperator.cs b/src/StrategyPatternExample/Operators/MultipleOperator.cs
index 5b075ce..e02c62a 100644
--- a/src/StrategyPatternExample/Operators/MultipleOperator.cs
+++ b/src/StrategyPatternExample/Operators/MultipleOperator.cs
@@ -1,6 +1,6 @@
 namespace StrategyPatternExample
 {
-    public class MultipleOperator : IMathOperator
+    public class MultipleOperator : IMathOperator<Operator>
     {
         public Operator Operator => Operator.Multiple;
 
diff --git a/src/StrategyPatternExample/Operators/SubtractOperator.cs b/src/StrategyPatternExample/Operators/SubtractOperator.cs
index dd5de7f..dc8d2c1 100644
--- a/src/StrategyPatternExample/Operators/SubtractOperator.cs
+++ b/src/StrategyPatternExample/Operators/SubtractOperator.cs
@@ -1,6 +1,6 @@
 namespace StrategyPatternExample
 {
-    public class SubtractOperator : IMathOperator
+    public class SubtractOperator : IMathOperator<Operator>
     {
         public Operator Operator => Operator.Substract;
 
diff --git a/src/StrategyPatternExample/Startup.cs b/src/StrategyPatternExample/Startup.cs
index 73dae71..5a64ac8 100644
--- a/src/StrategyPatternExample/Startup.cs
+++ b/src/StrategyPatternExample/Startup.cs
@@ -11,10 +11,10 @@ public void ConfigureServices(IServiceCollection services)
             services.AddMvc();
 
             services.AddScoped<IMathStrategy, MathStrategy>();
-            services.AddScoped<IMathOperator, AddOperator>();
-            services.AddScoped<IMathOperator, SubtractOperator>();
-            services.AddScoped<IMathOperator, MultipleOperator>();
-            services.AddScoped<IMathOperator, DivideOperator>();
+            services.AddScoped<IMathOperator<Operator>, AddOperator>();
+            services.AddScoped<IMathOperator<Operator>, SubtractOperator>();
+            services.AddScoped<IMathOperator<Operator>, MultipleOperator>();
+            services.AddScoped<IMathOperator<Operator>, DivideOperator>();
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
diff --git a/src/StrategyPatternExample/StrategyPatternExample.csproj b/src/StrategyPatternExample/StrategyPatternExample.csproj
index 965e3b7..b84de14 100644
--- a/src/StrategyPatternExample/StrategyPatternExample.csproj
+++ b/src/StrategyPatternExample/StrategyPatternExample.csproj
@@ -4,6 +4,14 @@
     <TargetFramework>netcoreapp2.0</TargetFramework>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
+    <LangVersion>7.3</LangVersion>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
+    <LangVersion>7.3</LangVersion>
+  </PropertyGroup>
+
   <ItemGroup>
     <Folder Include="wwwroot\" />
   </ItemGroup>